A more thorough explanation:

Definition: Legally, adverb. In a lawful way; in a manner that follows the law.

Examples:

• He obtained the property legally by following all the necessary procedures.
• The company was sued for not operating legally.
• She was advised to seek legal advice before signing the contract to ensure she was doing everything legally.

The examples illustrate that when something is done legally, it means that it is done in accordance with the law. In the first example, the person followed all the necessary procedures to obtain the property, which means they did it legally. In the second example, the company was sued for not following the law, which means they were not operating legally. In the third example, the person was advised to seek legal advice to ensure they were doing everything legally, which means they wanted to make sure they were following the law.